Hydrogen-bonding between benzoic acid and an N,N′-diethyl-substituted benzamidine

The synthesis and crystal structure of 4,N,N′-triethylbenzamidinium benzoate is reported in which the benzoate anion and the (E,E)-configured amidinium group are linked through two hydrogen bonds (with an N⋯O distance of 2.723 Å). Since an amidine (E,E) isomer was also observed for chloroform solutions of the complex, the binding mode in the crystal and in solution was analogous to that reported for unsubstituted amidines. The strong basicity of the N,N′-diethyl-substituted benzamidine (pKa 11.99±0.02 in water–dioxane, 1:1) was evident from potentiometric titrations.